In December, Forbes listed 16 billionaires in Africa, but Nigeria’s Ventures Magazine claims a much more exhaustive list that includes 55 African billionaires, according to a report in PerthNow.

There are far more mega-rich on the continent, the report says, but the number of Africans living in extreme poverty has also risen.

The wealthy often fiercely protect details about their fortunes, but the pan-African business magazine said it uncovered dozens of new billionaires by using “on-the-ground knowledge” to overcome hurdles that may have hampered other researchers.

Africa’s 55 billionaires include three women – the mother of Kenya’s president, a daughter of Angola’s president and a Nigerian oil tycoon and fashion designer, according to a BBCNews report. The richest man is Nigeria’s Aliko Dangote, worth $20.2 billion, Ventures said.

Of the 55, 20 are Nigerian, including several oil barons. South Africa and Egypt each have nine and eight billionaires, respectively, PerthNow reports.

The list is likely to reignite debate about inequality between rich and poor people in Africa, BBCNews reports.

World Bank said in April the number of people living in extreme poverty in Africa had risen in the past 30 years from 205 million to 414 million.

Ventures Magazine estimates the 55 billionaires’ combined worth at $143.88 billion. If that is true, their combined worth exceeds the nominal gross domestic product of all but four African countries, according to an International Monetary Fund list for 2012.

Africa’s richest woman is Nigerian Folorunsho Alakija, whose Fama Oil owns an offshore oil block, which she acquired in 1993 “at a relatively inexpensive price,” likely through a helpful connection, the magazine said.

The richest South African named is Nicky Oppenheimer, worth an estimated $6.5 billion. His wealth came largely from the diamond mines his family controlled for decades, operated by De Beers. Oppenheimer sold his family’s stake in De Beers two years ago.

The figure of 55 billionaires is “actually an underestimate” of Africa’s billionaires, Ventures founder Chi-Chi Okonjo, said.

Corruption is rife on the continent and the rule of law still unevenly applied, according to PerthNow. African business moguls often face accusations that their fortunes were illegitimately earned with help from political patrons.

The apparent rising number of ultra-rich Africans has come amid broader economic growth on the continent, which has seen an average 5 percent growth in gross domestic product since 2010.

But economic growth has not kept up with a rising population.

“There are more than twice as many extremely poor people living in sub-Saharan Africa today (414 million) than there were three decades ago (205 million),” World Bank said in April.

It is the only region where “the number of poor…has risen steadily and dramatically,” over the last 30 years, the bank said.